Sending Email

CAS presents the ability to notify users on select actions via email messages. Example actions include notification of risky authentication attempts or password reset links/tokens, etc. Configuring an email provider (i.e. Amazon Simple Email Service ) is a matter of defining SMTP settings. Each particular feature in need of email functionality should be able to gracefully continue in case settings are not defined.

Default support for email notifications is automatically enabled/included by the relevant modules using the following module:



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<dependency>
    <groupId>org.apereo.cas</groupId>
    <artifactId>cas-server-core-notifications</artifactId>
    <version>${cas.version}</version>
</dependency>





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implementation "org.apereo.cas:cas-server-core-notifications:${project.'cas.version'}"





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dependencyManagement {
    imports {
        mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
    }
}

dependencies {
    implementation "org.apereo.cas:cas-server-core-notifications"
}





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dependencies {
    implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${project.'cas.version'}")
    implementation platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)

    implementation "org.apereo.cas:cas-server-core-notifications"
}

You need not explicitly include this module in WAR Overlay configurations, except when there is a need to access components and APIs at compile-time.

Actuator Endpoints

The following endpoints are provided by CAS:

Reports back general health status of the system, produced by various monitors.

HealthComponent

HealthEndpoint.health()
org.springframework.boot.actuate.health.HealthEndpoint

Reports back general health status of the system, produced by various monitors.

HealthComponent

HealthEndpoint.healthForPath(java.lang.String…)
org.springframework.boot.actuate.health.HealthEndpoint


Email Message Body

The body of the email message that is defined in the CAS configuration can be constructed using the following strategies.

  • By default, the body of the email message that is defined in the CAS configuration is formatted using special placeholders for variables that are marked as ${...}. Such variables are substituted at runtime with the appropriate values available to the feature that is being used.

  • The configuration setting for the email message body can also accept a path to an external file (i.e. HTML). The contents of the file are processed for placeholder variables and values using the same default strategy.

    The email template file can also be processed via GStringTemplateEngine, if the path ends with the file extension .gtemplate. Input parameters are passed to the template which will substitute variables and expressions into placeholders in a template source text to produce the desired output.

    An example template, with variables and expressions such as firstname file would be:

    

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    Dear <%= firstname %> $lastname,
We <% if (accepted) print 'are pleased' else print 'regret' %> \
to inform you that your paper entitled
'$title' was ${ accepted ? 'accepted' : 'rejected' }.

    Note that the template file can be automatically localized per the available locale parameter. For example, if the template file is specified as EmailTemplate.html, and the available locale is de , CAS will automatically check for EmailTemplate_de.html first and will then fall back onto the default if the localized template file is not found.

  • The configuration setting for the email message body can also point to an external Groovy script to build the contents of the message body dynamically. The script may be designed as:

    

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    def run(Object[] args) {
    def values = (args[0] as Map).values()
    def logger = args[1]
    def locale = args.length == 3 ? args[2] : null
    
    logger.info("Parameters are {} with locale {}", args[0], locale)
    return String.format("%s, %s", values[0], values[1])
}

    The following parameters are passed to the script:

    Parameter Description
    parameters Map<String, ?> of parameters passed by CAS, depending on feature and/or context.
    logger The object responsible for issuing log messages such as logger.info(...).
    locale The object representing the available Locale, if any and available.

    The outcome of the script should be message body text.

    Simiarly, the email message body may be defined using an inline groovy script. In this case the configuration setting should be defined as:

    

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    groovy { return 'This is your email message!' }

    The script bindings prior to execution are prepared with a collection of parameters appropriate for that feature.

Email Strategies

The following approaches may be used to send emails.

Default

The default strategy uses the JavaMail API which provides a platform-independent and protocol-independent framework to build mail and messaging applications, primarily using SMTP:

The following settings may also need to be defined to describe the mail server settings:
  • spring.mail.default-encoding=UTF-8

    • Default MimeMessage encoding.

  • spring.mail.host=

    • SMTP server host. For instance, 'smtp.example.com'.

  • spring.mail.jndi-name=

    • Session JNDI name. When set, takes precedence over other Session settings.

  • spring.mail.password=

    • Login password of the SMTP server.

  • spring.mail.port=

    • SMTP server port.

  • spring.mail.properties=

    • Additional JavaMail Session properties.

  • spring.mail.protocol=smtp

    • Protocol used by the SMTP server.

  • spring.mail.test-connection=false

    • Whether to test that the mail server is available on startup.

  • spring.mail.username=

    • Login user of the SMTP server.

    Twilio SendGrid

    You may also instruct CAS to use Twilio SendGrid for sending emails. Support is enabled by including the the following module:

    

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    <dependency>
    <groupId>org.apereo.cas</groupId>
    <artifactId>cas-server-support-sendgrid</artifactId>
    <version>${cas.version}</version>
</dependency>

    		

    

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    implementation "org.apereo.cas:cas-server-support-sendgrid:${project.'cas.version'}"

    		

    

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    dependencyManagement {
    imports {
        mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
    }
}

dependencies {
    implementation "org.apereo.cas:cas-server-support-sendgrid"
}

    		

    

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    dependencies {
    implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${project.'cas.version'}")
    implementation platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)

    implementation "org.apereo.cas:cas-server-support-sendgrid"
}

    The following settings and properties are available from the CAS configuration catalog:

    The configuration settings listed below are tagged as Required in the CAS configuration metadata. This flag indicates that the presence of the setting may be needed to activate or affect the behavior of the CAS feature and generally should be reviewed, possibly owned and adjusted. If the setting is assigned a default value, you do not need to strictly put the setting in your copy of the configuration, but should review it nonetheless to make sure it matches your deployment expectations.

    The configuration settings listed below are tagged as Optional in the CAS configuration metadata. This flag indicates that the presence of the setting is not immediately necessary in the end-user CAS configuration, because a default value is assigned or the activation of the feature is not conditionally controlled by the setting value. In other words, you should only include this field in your configuration if you need to modify the default value or if you need to turn on the feature controlled by the setting.

    The configuration settings listed below are tagged as Third Party in the CAS configuration metadata. This flag indicates that the configuration setting is not controlled, owned or managed by the CAS ecosystem, and affects functionality that is offered by a third-party library, such as Spring Boot or Spring Cloud to CAS. For additional info, you might have to visit the third-party source to find more details.

  • spring.sendgrid.api-key=

    • SendGrid API key.

    org.springframework.boot.autoconfigure.sendgrid.SendGridProperties.
  • spring.sendgrid.proxy.host=

    • SendGrid proxy host.

    org.springframework.boot.autoconfigure.sendgrid.SendGridProperties$Proxy.
  • spring.sendgrid.proxy.port=

    • SendGrid proxy port.

    org.springframework.boot.autoconfigure.sendgrid.SendGridProperties$Proxy.

    Configuration Metadata

    The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.

    Be Selective

    This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.

    YAGNI

    Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.

    Naming Convention

    Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those that might be presented to the system via an external library or framework such as Spring Boot, etc.

    :information_source: Note

    When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value. The only possible exception to this rule is when naming actuator endpoints; The name of the actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.

    Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the way you intend.

    Validation

    Configuration properties are automatically validated on CAS startup to report issues with configuration binding, specially if defined CAS settings cannot be recognized or validated by the configuration schema. The validation process is on by default and can be skipped on startup using a special system property SKIP_CONFIG_VALIDATION that should be set to true. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.

    Indexed Settings

    CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be incremented by the adopter to allow for distinct multiple configuration blocks.

    Custom

    You may also define your own email sender that would be tasked to submit emails, etc using the following bean definition and by implementing EmailSender:

    

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    @Bean
public EmailSender emailSender() {
    return new MyEmailSender();   
}

    See this guide to learn more about how to register configurations into the CAS runtime.